Set 4GB mode register to support 4GB mode.

Signed-off-by: Liguo Zhang <redacted>
---
change in v3:
Only inline the computation of reg_4g_mode in mtk_i2c_set_4g_mode().
change in v2:
Define a static inline funtion mtk_i2c_set_4g_mode() for support 4g mode.
---
 drivers/i2c/busses/i2c-mt65xx.c | 42 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index aec8e6c..3c484f0 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c

@@ -60,6 +60,7 @@
 #define I2C_DMA_INT_FLAG_NONE		0x0000
 #define I2C_DMA_CLR_FLAG		0x0000
 #define I2C_DMA_HARD_RST		0x0002
+#define I2C_DMA_4G_MODE			0x0001
 
 #define I2C_DEFAULT_SPEED		100000	/* hz */
 #define MAX_FS_MODE_SPEED		400000

@@ -88,6 +89,8 @@ enum DMA_REGS_OFFSET {
 	OFFSET_RX_MEM_ADDR = 0x20,
 	OFFSET_TX_LEN = 0x24,
 	OFFSET_RX_LEN = 0x28,
+	OFFSET_TX_4G_MODE = 0x54,
+	OFFSET_RX_4G_MODE = 0x58,
 };
 
 enum i2c_trans_st_rs {

@@ -133,6 +136,7 @@ struct mtk_i2c_compatible {
 	unsigned char dcm: 1;
 	unsigned char auto_restart: 1;
 	unsigned char aux_len_reg: 1;
+	unsigned char support_33bits: 1;
 };
 
 struct mtk_i2c {

@@ -182,6 +186,7 @@ static const struct mtk_i2c_compatible mt6577_compat = {
 	.dcm = 1,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
+	.support_33bits = 0,
 };
 
 static const struct mtk_i2c_compatible mt6589_compat = {

@@ -190,6 +195,7 @@ static const struct mtk_i2c_compatible mt6589_compat = {
 	.dcm = 0,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
+	.support_33bits = 0,
 };
 
 static const struct mtk_i2c_compatible mt8173_compat = {

@@ -198,6 +204,7 @@ static const struct mtk_i2c_compatible mt8173_compat = {
 	.dcm = 1,
 	.auto_restart = 1,
 	.aux_len_reg = 1,
+	.support_33bits = 1,
 };
 
 static const struct of_device_id mtk_i2c_of_match[] = {

@@ -366,6 +373,11 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk,
 	return 0;
 }
 
+static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr)
+{
+	return (addr & BIT(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG;
+}
+

 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 			       int num, int left_num)
 {

@@ -373,6 +385,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 	u16 start_reg;
 	u16 control_reg;
 	u16 restart_flag = 0;
+	u32 reg_4g_mode = 0;